如何在GridView中显示Firebase存储镜像

Question

我是 Android 的新手，我正在学习gridview 。 我想将可绘制对象中的图像列表显示到gridview ，但我不知道如何在 gridview 中显示来自gridview存储的图像。

我看了很多教程，并且尝试了很多 Stackoverflow 答案，但我无法得到我需要的

我在 Firebase 存储中创建了一个新文件夹，我在那里上传了 6 张图像，我想显示gridview中的所有 6 张图像。

这是我如何显示可绘制图像的代码，我不知道如何加载 url 并且在滑行中我完全困惑并弄乱了自己

public class NewListCreate extends BottomSheetDialogFragment {


   int[] images = {R.drawable.menu, R.drawable.musicbox, R.drawable.shoppingbag, R.drawable.shoppingcart, R.drawable.wallet, R.drawable.weddingdress};
    int imageRes = images[0];

  

    public NewListCreate() {
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.new_list_create, container, false);

        ImageButton done = view.findViewById(R.id.done);
        final EditText listname = (EditText) view.findViewById(R.id.listname);
        final GridView gridView = (GridView) view.findViewById(R.id.gridview);

        final CustomAdpter customAdpter = new CustomAdpter(images, getContext());
        gridView.setAdapter(customAdpter);
        gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
                customAdpter.selectedImage = i;
                customAdpter.notifyDataSetChanged();
                imageRes = images[i];


            }
        });




        done.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                String itemname = listname.getText().toString();
                if (!TextUtils.isEmpty(listname.getText().toString())) {

                    startActivity(new Intent(getContext(), CheckslateHome.class).putExtra("data", itemname).putExtra("image", imageRes));
                    dismiss();
                } else {
                    Toast.makeText(getContext(), "List Name not Empty ", Toast.LENGTH_SHORT).show();
                }

            }

        });


        return view;


    }


    public class CustomAdpter extends BaseAdapter {

        public int selectedImage = 0;
        private int[] icons;
        private Context context;
        private LayoutInflater layoutInflater;

        public CustomAdpter(int[] icons, Context context) {
            this.icons = icons;
            this.context = context;
            this.layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        }

        @Override
        public int getCount() {
            return icons.length;
        }

        @Override
        public Object getItem(int i) {
            return null;
        }

        @Override
        public long getItemId(int i) {
            return 0;
        }

        @Override
        public View getView(int i, View view, ViewGroup viewGroup) {

            if (view == null) {
                view = layoutInflater.inflate(R.layout.image_list, viewGroup, false);

            }
            StorageReference storageReference = FirebaseStorage.getInstance().getReference();
            ImageView imageicons = view.findViewById(R.id.image);

            if (i < icons.length) {

                imageicons.setImageResource(icons[i]);

                if (i != selectedImage) {
                    imageicons.setImageAlpha(50);
                }
                imageicons.setScaleType(ImageView.ScaleType.CENTER_CROP);
                // imageicons.setLayoutParams(new GridView.LayoutParams(150, 150));
                if (i == selectedImage) {

                    view.setBackgroundColor(Color.WHITE);
                } else {
                    view.setBackgroundColor(Color.TRANSPARENT);
                }
            }
            ;


            return view;
        }
    }
}

这里是firebase的存储信息

Answer 1

我使用以下代码在我的应用程序中做了一个小而快速的演示，结果是这样的

对于 gridAdappter 我有这个：

public class GridAdapter extends BaseAdapter {
Context context;
private final String[] values;
private final String[] images;
View view;
LayoutInflater layoutInflater;

public GridAdapter(Context context, String[] values, String[] images) {
    this.context = context;
    this.values = values;
    this.images = images;
}

@Override
public int getCount() {
    return values.length;
}

@Override
public Object getItem(int position) {
    return null;
}

@Override
public long getItemId(int position) {
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    layoutInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    if(convertView==null)
    {
        view = new View(context);
        view=layoutInflater.inflate(R.layout.single_item,null);
        ImageView imageView = view.findViewById(R.id.imageView);
        TextView textView = view.findViewById(R.id.textView);
        Glide.with(context).load(images[position]).into(imageView);
        textView.setText(values[position]);
    }
    return view;
}

}

对于我拥有GridView的活动，我这样做了：

  gridView = findViewById(R.id.gridView) ;

   databaseReference = FirebaseDatabase.getInstance().getReference().child("Posts");
   databaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
       @Override
       public void onDataChange(@NonNull DataSnapshot snapshot) {
           for(DataSnapshot dataSnapshot:snapshot.getChildren())
           {
               if(i<19)
               {
                   Post post = dataSnapshot.getValue(Post.class);
                   images[i]=post.getpImage();
                   values[i]=post.getpTitle();
                   i++;
               }
           }
           GridAdapter gridAdapter = new GridAdapter(getApplicationContext(),values,images);
           gridView.setAdapter(gridAdapter);
       }

       @Override
       public void onCancelled(@NonNull DatabaseError error) {

       }
   });

我有一个对我的 Firebase 数据库的引用，以获取我存储在 Firebase 存储中的图片的 URL，我使用 class Post来获取信息，因为它对我来说更容易和更快。

您需要获取图像的 URL 并将它们添加到字符串数组图像中，如果您没有设置存储图片 URL 的数据库，请查看此文档以了解如何从存储中获取 URL。

以下是如何从 firebase 存储中为您的一张照片获取 URL

storageReference.child("icons/menu").getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
        @Override
        public void onSuccess(Uri uri) {
            images[0] = String.valueOf(uri);
            values[0] = "menu"
          //Here you can also add thiss
         /*GridAdapter gridAdapter = new 
                      GridAdapter(getApplicationContext(),values,images);
       gridView.setAdapter(gridAdapter);*/

        }
    }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {

        }
    });

Answer 2

我创建了一个FirebaseUtils class，从中我可以从中选择 static firebase 方法（没有双关语意）。
为了实现你想要的，只需创建一个循环然后调用下面的 downloadPic 方法

    for( int index = 0; index < noOfPhotos; index++ )
        FirebaseUtils.downloadPic( ivPic[index], "Photos/", image[index] );

ivPic是图像视图
picToDisplay是从存储中下载的图片
storageFolder是 firebase 上的文件夹 eg: Photos/
picToDownload是storageFolder中图片的名称
noOfPhotos是您拥有的照片数量，显然您可以设置查询并将它们加载到ArrayList中以方便使用

    //////////////////////////////////////////////////////////////////////////////////

    private static void loadPicIntoGlide( @NonNull ImageView ivPic, 
                                          @NonNull String picToDisplay )
    {
        if( picToDisplay.isEmpty() )
        {
            Glide.with( ivPic.getContext() )
                    .load( R.mipmap.ic_default_pic )
                    .into( ivPic );
        }
        else
        {
            Glide.with( ivPic.getContext() )
                    .load( picToDisplay )
                    .into( ivPic );
        }
    }

    ///////////////////////////////////////////////////////////////////////////////////


    public static void downloadPic( @NonNull ImageView ivPicView,
                                    @NonNull String storageFolder,
                                    @NonNull String picToDownload )
    {
        StorageReference storageRef = FirebaseStorage.getInstance().getReference();
        Uri uri = Uri.fromFile( new File( picToDownload ) );
        StorageReference storageReference = storageRef.child( 
               storageFolder + picToDownload );

        storageReference.getDownloadUrl().addOnSuccessListener( 
                                                new OnSuccessListener<Uri>()
        {
            @Override
            public void onSuccess( Uri uri )
            {
                String actPic = uri.toString();
                loadPicIntoGlide( ivPicView, actPic );
            }
        } )
        .addOnFailureListener( new OnFailureListener()
        {
            @Override
            public void onFailure( @NonNull Exception e )
            {
                loadPicIntoGlide( ivPicView, "" );
            }
        } );
    }

Answer 3

public class CustomAdpter extends BaseAdapter {

FirebaseStorage firebaseStorage = FirebaseStorage.getInstance();    

private Context context;

public CustomAdapter(Context c) {
    context = c;
}

public int getCount() {
    return thumbId.length;
}

public Object getItem(int position) {
    return null;
}

public long getItemId(int position) {
    return 0;
}

// create a new ImageView for each item referenced by the Adapter
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    if (convertView == null) {
        // if it's not recycled, initialize some attributes
        imageView = new ImageView(context);
        imageView.setLayoutParams(new GridView.LayoutParams(200, 200));
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        imageView.setPadding(8, 8, 8, 8);
    } else {
        imageView = (ImageView) convertView;
    }

    imageView.setImageResource(thumbId [position]);




    return imageView;
}

// references to our images
public Integer[] thumbId = {

        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7,
        R.drawable.sample_0, R.drawable.sample_1,
        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7,
        R.drawable.sample_0, R.drawable.sample_1,
        R.drawable.sample_2, R.drawable.sample_3,
        R.drawable.sample_4, R.drawable.sample_5,
        R.drawable.sample_6, R.drawable.sample_7
};

}